For example, as described in Japanese Unexamined Patent Application, First Publication No. 2002-296779 (patent reference 1), a chemically amplified photoresist composition obtained by using a KrF excimer laser, an ArF excimer laser, an F2 excimer laser, an EUV (extreme UV ray) or an EB (electron beam) or the like for a light source (radiation source) typically contains a resin component (A), an acid-generating component (B) for generating an acid under exposure and an organic solvent (C) capable of dissolving these components.
A resist pattern having high resolution, high sensitivity and an excellent shape or the like is required of the chemically amplified photoresist composition.
A resist pattern having high resolution of 0.15 μm or lower has recently been demanded, and the reduction of the defects (surface defects) of the resist pattern after development over that of a conventional resist pattern has been further demanded in addition to the characteristics.
The defect typically is an actual nonconformity defection when the resist pattern after development is observed from directly above by a surface defect observation apparatus (trade name “KLA”) manufactured by, for example, KLA Tencor Company. This nonconformity is, for example, scum, bubbles, waste or a bridge between resist patterns or the like after development.
So as to reduce the defects, improvements in the resist composition such as a resin component of the resist composition, an acid-generating component and a solvent component have been mainly attempted [Japanese Unexamined Patent Application, First Publication No. 2001-56556 (patent reference 2)].
While a resist solution (a photoresist composition of a solution state) is stored, a storage stability characteristic as a resist solution (while the photoresist composition is stored, solid foreign matter is generated in the photoresist composition; storage stability) in which minute particles are generated also poses a problem, and the improvement thereof is desired.
For the improvement of the storage stability characteristic as a resist solution, the improvement of the resist composition has been attempted in the same manner as the above case [Japanese Published Unexamined Patent Application No. 2001-22072 (patent reference 3)].
[Patent reference 1] Japanese Unexamined Patent Application, First Publication No. 2002-296779
[Patent reference 2] Japanese Unexamined Patent Application, First Publication No. 2001-56556
[Patent reference 3] Japanese Unexamined Patent Application, First Publication No. 2001-22072
[Patent reference 4] Japanese Unexamined Patent Application, First Publication No. 2002-62667
[Patent reference 5] Japanese Unexamined Patent Application, First Publication No. 2001-350266